Muscular exercise apparatus have used weights, spring loaded mechanical devices, and elastic cable to provide resistance to movement of a user's torso, head or limbs by physical exertion as a means for strengthening specific muscles. Elastic cable prior art exercise devices include those shown in U.K. patents 27,611, 26,180, and 1,112,114, and in U.S. Pat. Nos. 1,965,511, and 4,779,867. The prior art does not show means for adjusting cable length nor safety provisons for preventing injury to a user in the event of failure of means anchoring a cable.